I am using the Mediatrix 1204 4 port FXO gateway to connect to the PSTN and 3CX Phone System v3.0.1699.0. I got it working for both outgoing and incoming calls, however for incoming calls they are getting disconnected after precisely 30-33 seconds (with voice activity). This is not a Mediatrix issue because using Asterisk with the same configuration, it does not disconnect by itself. I have a feeling the problem may be with both 3CX and Mediatrix. Perhaps 3CX is waiting for specific queries from the Mediatrix but isn't getting them. Here's the last few log lines (in reverse chronological order): 18:11:54.876 StunClient:rocess STUN resolved external IP=18.104.22.168[I masked the IP here on purpose]:62621 by server 22.214.171.124 17:52:26.629 StratLink:nHangUp Call(C:5): got Hang-Up from Ln:10000@Mediatrix; reason: BYE 17:51:54.129 StunClient:rocess STUN resolved external IP=126.96.36.199[I masked the IP here on purpose]:63409 by server 188.8.131.52 17:51:43.817 CallLegImpl:nConnected Established media channel for Ln:10000@Mediatrix: remote=192.168.0.25:5004; local=192.168.0.10:40900 Would you have any ideas as to what may be the issue?